This invention generally relates to a radiopaque catheter tip for use with a medical device.
Catheters are disclosed in U.S. Pat. Nos. 4,531,943; 4,547,193; 4,806,182; and 5,405,380. Catheter assemblies are disclosed in U.S. Pat. Nos. 4,646,742; 5,240,537; 5,364,357; 5,403,292; 5,545,151; and 5,599,325. Additional catheters are disclosed in U.S. Pat. Nos. 5,045,072; 5,171,232; and 5,221,270.
All references cited herein, including the foregoing, are incorporated herein in their entireties for all purposes.
The invention relates to a radiopaque catheter tip which may be joined to a medical device such as a catheter or may be manufactured in one-piece as part of the catheter. Use of the invention advantageously improves placement and imaging of a medical device during surgical procedures.
In sum, the invention relates to a radiopaque catheter tip and assembly. The assembly includes a first tube having a proximal end, a distal end, an inside diameter, an outside diameter, a first layer, a second layer and a third layer. The second layer includes one or more elongated elements having an average linear attenuation coefficients per unit of length in the range of about 5.46 to about 151.53 cmxe2x88x921 at 50 KeV disposed over at least a portion of the first layer. The third layer is disposed over the second layer. A second tube includes a proximal end, distal end, inside diameter and outside diameter. The first tube is positioned distal of the second tube and is associated with the second tube. The one or more elongated elements may be made of at least one of platinum, iridium, nickel, titanium or their alloys. The first layer may include at least one of a thermoplastic or polymer material, and the third layer may include a material having an average durometer hardness greater than the first layer. The first tube may have an average radiopacity per unit of length greater than the second tube. The first layer may be made of one of PTFE, high density polyethylene (HDPE), polyethylene (PE), Arnitel, nylon and the third layer may be made of one of polyether ester elastomer, Hytrel, Peba-nylon or nylon. The elongated elements may intersect at one or more locations and form an angle ranging from about 5 degrees to about 175 degrees. The elongated elements may be disposed in a generally helical pattern and form an elongated tube having a wall with openings between elements. The elongated elements may be formed in a generally helical coil. The first tube may have a length of from about 0.1 cm to about 20 cm. The elongated elements may be made of at least one of a wire, filament or ribbon. The elongated elements may have an average diameter or thickness between about 0.001 inches and about 0.005 inches.
The invention also relates to a radiopaque tip including a first layer having an outside surface, a proximal end, and a distal end. An intermediate layer includes one or more first elongated elements and one or more second elongated elements. The first elongated elements have an average linear attenuation coefficients per unit of length in the range of from about 5.46 to about 151.53 cmxe2x88x921 at 50 KeV and are disposed over a portion of the first layer. The second elongated elements have an average linear attenuation coefficients per unit of length less than about 100 cmxe2x88x921 at 50 KeV and are disposed over a portion of the first layer. A third layer of material is disposed over the intermediate layer. At least two of the layers are bonded together. The invention also relates to a radiopaque tip including a tube including a plurality of layers, a proximal end, a distal end, a length, a lumen, and at least one radiopaque member having an average linear attenuation coefficients per unit of length in the range of from about 5.46 to about 151.53 cmxe2x88x921 at 50 KeV. The at least one radiopaque member is disposed over at least a portion of the length of the tube. The tube is adapted to be cut to a length and connected to a distal portion of a medical device. The at least one radiopaque member may be configured in a braided pattern such that openings are formed between the wires prior to a heating process.
The invention also relates to a radiopaque tip including a first layer of material forming a tube and a second layer. The second layer includes one or more radiopaque metal wires having an average thickness ranging from about 0.001 inches to about 0.005 inches that is formed in a pattern over at least a portion of the first layer of material. The first layer and the second layer are associated with one other and the radiopaque tip has sufficient flexibility for use in a body lumen when connected to a medical device.
The invention also relates to a radiopaque tip including a first layer having a diameter and a second layer disposed on the first layer. The second layer includes one or more first metal wires made of a first material having an atomic number greater than about 70 and less than about 83. The first metal wires form one or more angles between crossing wires. The one or more angles range from about 5 degrees to about 175 degrees. The second layer includes one or more second metal wires made of a second material having a lower average radiopacity than the first metal wires. The second metal wires form one or more angles between crossing wires. The one or more angles ranging from about 5 degrees to about 175 degrees. The one or more first metal wires are positioned distally of the second metal wires. A third layer is disposed on the second layer. The first, second and third layers are associated with at least one of the other. The first and second metal wires may overlap and be coaxial oriented over at least a portion of the catheter. The angle between crossing wires may decrease distally and the flexibility of the radiopaque catheter tip may increase distally. The angle between crossing wires may increases distally and the flexibility of the radiopaque catheter tip may decrease distally. The first and the second metal wires may be separated longitudinally or be separated radially apart from one another by a space or a material.
The invention also relates to a method of forming a radiopaque catheter tip including providing a first layer of material in the form of a tube; providing a second layer including one or more elongated elements having radiopaque characteristics; disposing the elongated elements over at least a portion of the first layer; providing a third layer of material; disposing the third layer over at least a portion of the elongated elements; applying radial compression to the layers; heating the layers at a temperature for a period of time to form a radiopaque tube having an end; providing a second tube having an end; and joining the end of the radiopaque tube to the end of the second tube. The method may further include prior to joining the end of the radiopaque tube to the end of a second tube, placing the radiopaque tube in about the same longitudinal axis and adjacent the second tube; applying shrink wrap tubing over at least a portion of the radiopaque tube, a joint portion between the radiopaque tube and the second tube, and the second tube; heating at least the joint portion to a condition such that the shrink wrap tubing radially compresses at least a portion of the radiopaque tube, a joint portion between the radiopaque tube and the second tube; and removing the shrink wrap tube. The method may further include prior to joining the end of the radiopaque tube to the end of a second tube, placing the radiopaque tube in about the same longitudinal axis and adjacent the second tube; applying shrink wrap tubing over at least a portion of the radiopaque tube, a joint portion between the radiopaque tube and the second tube, and the second tube; heating at least the joint portion at a temperature of about 230xc2x0 to about 340xc2x0 for about 20 seconds to about 80 seconds; and removing the shrink wrap tube. The method of forming a radiopaque catheter tip may further include after heating the layers, providing a length of the radiopaque tube; disposing the radiopaque tube on a mandrel; providing a length of the second tube; disposing the second tube on the mandrel tandemly adjacent the radiopaque tube; and heating the radiopaque tube and the second tube to a temperature for a period of time such that the materials bond and the two tubes are connected. The one or more layers may be heated above a glass transition temperature and less than a melting temperature.
The invention also relates to a tip including one or more elongated metal filaments embedded in polymer. The one or more elongated metal filaments include a metal having a linear attenuation coefficient per unit of length of from about 70 to about 120 cmxe2x88x921 at 50 KeV. The filaments may include at least one of platinum, tantalum, iridium, gold, bismuth, or alloys thereof. The tip may be disposed on a distal end of a catheter and have a greater flexibility than the distal end of the catheter. The one or more elongated filaments may be braided. The one or more elongated filaments may be coiled.
Still other objects and advantages of the present invention and methods of construction and use of the same will become readily apparent to those skilled in the art from the following detailed description, wherein only the preferred embodiments are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments and methods of construction and use, and its several details are capable of modification in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.